"What's really exciting
is that we got the Lightning Mapping Array set up before the
initial eruption," doctoral student Sonja Behnke said. "We're
getting data from the beginning of the eruptive phase of the
volcano. We're seeing everything from the beginning to the end."

When Alaska's Redoubt Volcano
started rumbling in January, a team of Tech researchers hurried
to south central Alaska to deploy a series of radio sensors.
When the volcano began erupting overnight on March 22 and 23,
the array of stations started returning clear and dramatic information
about the electricity created within volcanic plumes and the
resulting lightning.

"We're getting all the
data we hoped to get and a lot more," principal investigator
Dr. Ron Thomas said. "Absolutely, the quality and quantity
of the data will allow us to better understand the electrical
charge structure inside a volcanic plume. That should help us
understand how the plume is becoming electrified and how that
evolves over time."

Dr. Bradley Smull, associate
program director with the NSF, said the Redoubt Volcano data
is likely to help scientists understand fundamental electrical
mechanisms within plumes of ash, steam and other hot gases above
active volcanoes.

"Given a bit more time
to gather and digest the Lightning Mapping Array data, I'm sure
that exciting details of the plume-induced atmospheric electrical
structure will emerge," Smull said. "The opportunity
for both stand-alone analysis and comparisons with last year's
observations of Chaiten Volcano in Chile are extremely exciting."

Behnke, a second-year Ph.D.
student in physics, will spend the next few months - or the next
few years - processing and analyzing the data from Redoubt.

"We haven't looked at
the data in great detail yet," she said. "I'm still
pretty busy downloading all the data, making sure the stations
are still operating and documenting the eruptions."

Redoubt erupted explosively
about 20 times in the first seven days of activity, with seismic
activity decelerating in recent days. Most volcanic eruptions
have several distinct stages. In the case of Redoubt, a stage
of explosive activity is followed by a second stage that includes
dome-building and slow venting of ash, rock and gasses. Within
the individual explosive eruptions, different phases of electrical
activity are observed.

"First, we see an eruptive
or explosive phase," physics professor Paul Krehbiel said.
"Electrical activity is continuous and strong. We see a
lot of small electrical discharges as hot gasses come out of
the volcano."

The second phase involves the
ash cloud as it drifts away from the volcano with the wind. This
phase is punctuated by discrete lightning - or lightning bolts.

"After the explosion is
over, there is a subsequent phase of plume lightning," Krehbiel
said. "Full-fledged lightning occurs in the cloud of ash
and water both above and downwind of the volcano."

The Redoubt eruptions are not
over yet. After quieting down and appearing to go into a dome-building
phase, just before sunrise Saturday, April 4, the volcano blew
its top in the biggest eruption so far.

"The lightning activity
was as strong as or stronger than we have seen in large Midwestern
thunderstorms," Krehbiel said. "The radio frequency
noise was so strong and continuous that people living in the
area would not have been able to watch broadcast VHF television
stations."

Lightning Mapping Arrays are
set up in several areas of the country for research studies and
are becoming increasingly used by meteorologists to help issue
severe weather warnings. The portable stations have been deployed
at active volcanoes only twice before.

In 2006, the New Mexico Tech
team deployed a two-station array at Mt. St. Augustine, also
in south-central Alaska. In 2008, the group deployed a four-station
array at Chaiten Volcano in Chile. In both of those instances,
the array was not in place until after the initial eruptive phase.
In contrast, Redoubt Volcano was very cooperative and the team's
advance planning paid major dividends.

"Redoubt, in some ways,
has been a perfect laboratory," Krehbiel said. "It
erupted on schedule and gave us two months notice."

The National Science Foundation
awarded New Mexico Tech a three-year grant to study volcanic
lightning in 2007, with the University of Alaska Fairbanks and
the Alaska Volcano Observatory as collaborators. Thomas said
some colleagues doubted that the Tech team would be able to capture
data from an initial eruption.

"This is really exciting
for us," Thomas said. "You plan and hope you can do
something like this once in a lifetime. It's hard to judge a
volcano before it happens and get the sensors set up before it
erupts."

"I certainly wouldn't
have been surprised if the three years elapsed without us getting
the data we wanted," Behnke said. "The stars had to
align just right."

Krehbiel said advance warning
from the Volcano Observatory was critical to the mission. In
late 2008, Redoubt showed initial signs of small-scale seismic
activity. Steve McNutt and his colleagues at the Alaska Volcano
Observatory started scouting locations for Tech's sensors. In
Socorro, Krehbiel, Thomas and the rest of the team had several
stations ready for deployment.

Krehbiel, Thomas and Behnke
made the initial trek to Alaska in late January to join McNutt
to set up four Lightning Mapping Array stations, which are portable
sensors designed and built at New Mexico Tech. Each station weighs
about 40 pounds and has its electronics contained within a modified
picnic cooler. The sensing stations can store up to three months
of radio wave information and are capable of running unattended.

A few weeks later in February,
doctoral student Harald Edens and Krehbiel returned to Alaska
to set up the wireless internet feeds from each station, so they
could access data in New Mexico.

Just two days before the initial
eruption, Edens made a mad dash from New Mexico to Alaska to
service a station that was misbehaving. Within 24 hours of Edens'
departure from Alaska, Redoubt erupted, sending an ash plume
more than 8 kilometers into the atmosphere.

"This volcano, in the
space of a week, has had several major eruptions that have produced
prolific lightning," Krehbiel said.

The four Lightning Mapping
Array stations are along a roughly 60 mile stretch of on the
east side of Cook Inlet across from the volcano. Thomas, Krehbiel,
Behnke, and McNutt found four cooperative places in accessible
locations to host the stations. The northernmost sensor is at
a school teacher's house in Nikiski. The second station is at
a fire station south of Kenai. In Clam Gulch, Thomas and crew
are borrowing space at the Clam Gulch Lodge. The southernmost
sensor is at the K-12 public school in Ninilchik.

When Redoubt Volcano erupted,
Tech scientists and researchers had their first ever data from
an initial eruption of an explosive volcano.

"With Redoubt we have
data for all the eruptions and will be well posed to examine
trends as a function of time," said McNutt, Coordinating
Scientist at the Alaska Volcano Observatory. "We are accumulating
a fantastic data set of the eruptions."

In addition to the Lightning
Mapping Array, AVO is gathering data from 11 local seismic stations,
two infrasound arrays and two radar stations. More data are being
recorded by webcam, remote sensing, gas flights, direct observations
and sampling.

Ideally, a Lightning Mapping
Array would include at least six stations. Permanent arrays include
up to 12 sensing stations. Still, with four stations, New Mexico
Tech researchers will be able to produce 3-D images.

Signals from four stations
will readily produce a two-dimensional image. With more careful
analysis, Behnke and Thomas will be able to create three-dimensional
images. They will be aided in this by three of the sensing stations
being located on the edge of the coastal bluff overlooking Cook
Inlet and receiving interference signals - a secondary radio
wave reflects off the inlet's water surface.

"We used the sea surface
reflections in our study of the Augustine eruption" Thomas
said, "and are ready to use them again for the Redoubt eruptions."

Radio waves created by lightning
travel about one foot per nanosecond. Each mapping station measures
the arrival time of radio signals to the nearest 40 nanoseconds,
so that the sensors pinpoint the distance to the lightning source
within about 40 feet, Krehbiel said.

Thousands of individual segments
of a single lightning stroke can be mapped with the Lightning
Mapping Array and later analyzed on high-end computers to reveal
how lightning initiates and spreads throughout a thunderstorm
... or within a volcanic plume.

"We receive radio bursts
of noise generated from sparks of lightning, just like the static
you hear on your car radio during a thunderstorm," Thomas
said. "We will use our sensing stations to locate the lightning
and track its path."

Tech's pioneering lightning
research has led to a series of scientific and technological
breakthroughs, including proprietary sensing technology - the
Lightning Mapping Array - that allows scientists, meteorologists
and storm chasers to pierce the veil of clouds to "see"
lightning as it occurs.

"With each lightning flash,
we'll be able to monitor how it moves through the clouds and
where it goes," Thomas said. "If we take all our theories
about lightning created in thunderstorms, we can learn about
both types of lightning."

Note:

New Mexico Tech is a collaborator
with the Geophysical Institute/Alaska Volcano Observatory on
volcanic lightning studies of Redoubt Volcano. GI/AVO helped
NMT position four lightning measuring arrays (LMAs) along the
Kenai Peninsula shortly before Redoubt began to erupt this year.
Data is currently
coming in. Currently, volcanic lightning is not widely understood,
and the LMAs have collected data from the very start of Redoubt's
eruption